<?php
/**
*
* This file is part of the phpBB Forum Software package.
*
* @copyright (c) phpBB Limited <https://www.phpbb.com>
* @license GNU General Public License, version 2 (GPL-2.0)
*
* For full copyright and license information, please see
* the docs/CREDITS.txt file.
*
*/
namespace phpbb\db\tools;
/**
* Database Tools for handling cross-db actions such as altering columns, etc.
* Currently not supported is returning SQL for creating tables.
*/
class tools implements tools_interface
{
/**
* Current sql layer
*/
var $sql_layer = '';
/**
* @var object DB object
*/
var $db = null;
/**
* The Column types for every database we support
* @var array
*/
var $dbms_type_map = array();
/**
* Get the column types for every database we support
*
* @return array
*/
static public function get_dbms_type_map()
{
return array(
'mysql_41' => array(
'INT:' => 'int(%d)',
'BINT' => 'bigint(20)',
'ULINT' => 'INT(10) UNSIGNED',
'UINT' => 'mediumint(8) UNSIGNED',
'UINT:' => 'int(%d) UNSIGNED',
'TINT:' => 'tinyint(%d)',
'USINT' => 'smallint(4) UNSIGNED',
'BOOL' => 'tinyint(1) UNSIGNED',
'VCHAR' => 'varchar(255)',
'VCHAR:' => 'varchar(%d)',
'CHAR:' => 'char(%d)',
'XSTEXT' => 'text',
'XSTEXT_UNI'=> 'varchar(100)',
'STEXT' => 'text',
'STEXT_UNI' => 'varchar(255)',
'TEXT' => 'text',
'TEXT_UNI' => 'text',
'MTEXT' => 'mediumtext',
'MTEXT_UNI' => 'mediumtext',
'TIMESTAMP' => 'int(11) UNSIGNED',
'DECIMAL' => 'decimal(5,2)',
'DECIMAL:' => 'decimal(%d,2)',
'PDECIMAL' => 'decimal(6,3)',
'PDECIMAL:' => 'decimal(%d,3)',
'VCHAR_UNI' => 'varchar(255)',
'VCHAR_UNI:'=> 'varchar(%d)',
'VCHAR_CI' => 'varchar(255)',
'VARBINARY' => 'varbinary(255)',
),
'oracle' => array(
'INT:' => 'number(%d)',
'BINT' => 'number(20)',
'ULINT' => 'number(10)',
'UINT' => 'number(8)',
'UINT:' => 'number(%d)',
'TINT:' => 'number(%d)',
'USINT' => 'number(4)',
'BOOL' => 'number(1)',
'VCHAR' => 'varchar2(255)',
'VCHAR:' => 'varchar2(%d)',
'CHAR:' => 'char(%d)',
'XSTEXT' => 'varchar2(1000)',
'STEXT' => 'varchar2(3000)',
'TEXT' => 'clob',
'MTEXT' => 'clob',
'XSTEXT_UNI'=> 'varchar2(300)',
'STEXT_UNI' => 'varchar2(765)',
'TEXT_UNI' => 'clob',
'MTEXT_UNI' => 'clob',
'TIMESTAMP' => 'number(11)',
'DECIMAL' => 'number(5, 2)',
'DECIMAL:' => 'number(%d, 2)',
'PDECIMAL' => 'number(6, 3)',
'PDECIMAL:' => 'number(%d, 3)',
'VCHAR_UNI' => 'varchar2(765)',
'VCHAR_UNI:'=> array('varchar2(%d)', 'limit' => array('mult', 3, 765, 'clob')),
'VCHAR_CI' => 'varchar2(255)',
'VARBINARY' => 'raw(255)',
),
'sqlite3' => array(
'INT:' => 'INT(%d)',
'BINT' => 'BIGINT(20)',
'ULINT' => 'INTEGER UNSIGNED',
'UINT' => 'INTEGER UNSIGNED',
'UINT:' => 'INTEGER UNSIGNED',
'TINT:' => 'TINYINT(%d)',
'USINT' => 'INTEGER UNSIGNED',
'BOOL' => 'INTEGER UNSIGNED',
'VCHAR' => 'VARCHAR(255)',
'VCHAR:' => 'VARCHAR(%d)',
'CHAR:' => 'CHAR(%d)',
'XSTEXT' => 'TEXT(65535)',
'STEXT' => 'TEXT(65535)',
'TEXT' => 'TEXT(65535)',
'MTEXT' => 'MEDIUMTEXT(16777215)',
'XSTEXT_UNI'=> 'TEXT(65535)',
'STEXT_UNI' => 'TEXT(65535)',
'TEXT_UNI' => 'TEXT(65535)',
'MTEXT_UNI' => 'MEDIUMTEXT(16777215)',
'TIMESTAMP' => 'INTEGER UNSIGNED', //'int(11) UNSIGNED',
'DECIMAL' => 'DECIMAL(5,2)',
'DECIMAL:' => 'DECIMAL(%d,2)',
'PDECIMAL' => 'DECIMAL(6,3)',
'PDECIMAL:' => 'DECIMAL(%d,3)',
'VCHAR_UNI' => 'VARCHAR(255)',
'VCHAR_UNI:'=> 'VARCHAR(%d)',
'VCHAR_CI' => 'VARCHAR(255)',
'VARBINARY' => 'BLOB',
),
);
}
/**
* A list of types being unsigned for better reference in some db's
* @var array
*/
var $unsigned_types = array('ULINT', 'UINT', 'UINT:', 'USINT', 'BOOL', 'TIMESTAMP');
/**
* This is set to true if user only wants to return the 'to-be-executed' SQL statement(s) (as an array).
* This mode has no effect on some methods (inserting of data for example). This is expressed within the methods command.
*/
var $return_statements = false;
/**
* Constructor. Set DB Object and set {@link $return_statements return_statements}.
*
* @param \phpbb\db\driver\driver_interface $db Database connection
* @param bool $return_statements True if only statements should be returned and no SQL being executed
*/
public function __construct(\phpbb\db\driver\driver_interface $db, $return_statements = false)
{
$this->db = $db;
$this->return_statements = $return_statements;
$this->dbms_type_map = self::get_dbms_type_map();
// Determine mapping database type
switch ($this->db->get_sql_layer())
{
case 'mysqli':
$this->sql_layer = 'mysql_41';
break;
default:
$this->sql_layer = $this->db->get_sql_layer();
break;
}
}
/**
* Setter for {@link $return_statements return_statements}.
*
* @param bool $return_statements True if SQL should not be executed but returned as strings
* @return null
*/
public function set_return_statements($return_statements)
{
$this->return_statements = $return_statements;
}
/**
* {@inheritDoc}
*/
function sql_list_tables()
{
switch ($this->db->get_sql_layer())
{
case 'mysqli':
$sql = 'SHOW TABLES';
break;
case 'sqlite3':
$sql = 'SELECT name
FROM sqlite_master
WHERE type = "table"
AND name <> "sqlite_sequence"';
break;
case 'oracle':
$sql = 'SELECT table_name
FROM USER_TABLES';
break;
}
$result = $this->db->sql_query($sql);
$tables = array();
while ($row = $this->db->sql_fetchrow($result))
{
$name = current($row);
$tables[$name] = $name;
}
$this->db->sql_freeresult($result);
return $tables;
}
/**
* {@inheritDoc}
*/
function sql_table_exists($table_name)
{
$this->db->sql_return_on_error(true);
$result = $this->db->sql_query_limit('SELECT * FROM ' . $table_name, 1);
$this->db->sql_return_on_error(false);
if ($result)
{
$this->db->sql_freeresult($result);
return true;
}
return false;
}
/**
* {@inheritDoc}
*/
function sql_create_table($table_name, $table_data)
{
// holds the DDL for a column
$columns = $statements = array();
if ($this->sql_table_exists($table_name))
{
return $this->_sql_run_sql($statements);
}
// Begin transaction
$statements[] = 'begin';
// Determine if we have created a PRIMARY KEY in the earliest
$primary_key_gen = false;
// Determine if the table requires a sequence
$create_sequence = false;
// Begin table sql statement
$table_sql = 'CREATE TABLE ' . $table_name . ' (' . "\n";
// Iterate through the columns to create a table
foreach ($table_data['COLUMNS'] as $column_name => $column_data)
{
// here lies an array, filled with information compiled on the column's data
$prepared_column = $this->sql_prepare_column_data($table_name, $column_name, $column_data);
if (isset($prepared_column['auto_increment']) && $prepared_column['auto_increment'] && strlen($column_name) > 26) // "${column_name}_gen"
{
trigger_error("Index name '${column_name}_gen' on table '$table_name' is too long. The maximum auto increment column length is 26 characters.", E_USER_ERROR);
}
// here we add the definition of the new column to the list of columns
$columns[] = "\t {$column_name} " . $prepared_column['column_type_sql'];
// see if we have found a primary key set due to a column definition if we have found it, we can stop looking
if (!$primary_key_gen)
{
$primary_key_gen = isset($prepared_column['primary_key_set']) && $prepared_column['primary_key_set'];
}
// create sequence DDL based off of the existence of auto incrementing columns
if (!$create_sequence && isset($prepared_column['auto_increment']) && $prepared_column['auto_increment'])
{
$create_sequence = $column_name;
}
}
// this makes up all the columns in the create table statement
$table_sql .= implode(",\n", $columns);
// we have yet to create a primary key for this table,
// this means that we can add the one we really wanted instead
if (!$primary_key_gen)
{
// Write primary key
if (isset($table_data['PRIMARY_KEY']))
{
if (!is_array($table_data['PRIMARY_KEY']))
{
$table_data['PRIMARY_KEY'] = array($table_data['PRIMARY_KEY']);
}
switch ($this->sql_layer)
{
case 'mysql_41':
case 'sqlite3':
$table_sql .= ",\n\t PRIMARY KEY (" . implode(', ', $table_data['PRIMARY_KEY']) . ')';
break;
case 'oracle':
$table_sql .= ",\n\t CONSTRAINT pk_{$table_name} PRIMARY KEY (" . implode(', ', $table_data['PRIMARY_KEY']) . ')';
break;
}
}
}
// close the table
switch ($this->sql_layer)
{
case 'mysql_41':
// make sure the table is in UTF-8 mode
$table_sql .= "\n) CHARACTER SET `utf8` COLLATE `utf8_bin`;";
$statements[] = $table_sql;
break;
case 'sqlite3':
$table_sql .= "\n);";
$statements[] = $table_sql;
break;
case 'oracle':
$table_sql .= "\n)";
$statements[] = $table_sql;
// do we need to add a sequence and a tigger for auto incrementing columns?
if ($create_sequence)
{
// create the actual sequence
$statements[] = "CREATE SEQUENCE {$table_name}_seq";
// the trigger is the mechanism by which we increment the counter
$trigger = "CREATE OR REPLACE TRIGGER t_{$table_name}\n";
$trigger .= "BEFORE INSERT ON {$table_name}\n";
$trigger .= "FOR EACH ROW WHEN (\n";
$trigger .= "\tnew.{$create_sequence} IS NULL OR new.{$create_sequence} = 0\n";
$trigger .= ")\n";
$trigger .= "BEGIN\n";
$trigger .= "\tSELECT {$table_name}_seq.nextval\n";
$trigger .= "\tINTO :new.{$create_sequence}\n";
$trigger .= "\tFROM dual;\n";
$trigger .= "END;";
$statements[] = $trigger;
}
break;
}
// Write Keys
if (isset($table_data['KEYS']))
{
foreach ($table_data['KEYS'] as $key_name => $key_data)
{
if (!is_array($key_data[1]))
{
$key_data[1] = array($key_data[1]);
}
$old_return_statements = $this->return_statements;
$this->return_statements = true;
$key_stmts = ($key_data[0] == 'UNIQUE') ? $this->sql_create_unique_index($table_name, $key_name, $key_data[1]) : $this->sql_create_index($table_name, $key_name, $key_data[1]);
foreach ($key_stmts as $key_stmt)
{
$statements[] = $key_stmt;
}
$this->return_statements = $old_return_statements;
}
}
// Commit Transaction
$statements[] = 'commit';
return $this->_sql_run_sql($statements);
}
/**
* {@inheritDoc}
*/
function perform_schema_changes($schema_changes)
{
if (empty($schema_changes))
{
return;
}
$statements = array();
$sqlite = false;
// For SQLite we need to perform the schema changes in a much more different way
if ($this->db->get_sql_layer() == 'sqlite3' && $this->return_statements)
{
$sqlite_data = array();
$sqlite = true;
}
// Drop tables?
if (!empty($schema_changes['drop_tables']))
{
foreach ($schema_changes['drop_tables'] as $table)
{
// only drop table if it exists
if ($this->sql_table_exists($table))
{
$result = $this->sql_table_drop($table);
if ($this->return_statements)
{
$statements = array_merge($statements, $result);
}
}
}
}
// Add tables?
if (!empty($schema_changes['add_tables']))
{
foreach ($schema_changes['add_tables'] as $table => $table_data)
{
$result = $this->sql_create_table($table, $table_data);
if ($this->return_statements)
{
$statements = array_merge($statements, $result);
}
}
}
// Change columns?
if (!empty($schema_changes['change_columns']))
{
foreach ($schema_changes['change_columns'] as $table => $columns)
{
foreach ($columns as $column_name => $column_data)
{
// If the column exists we change it, else we add it ;)
if ($column_exists = $this->sql_column_exists($table, $column_name))
{
$result = $this->sql_column_change($table, $column_name, $column_data, true);
}
else
{
$result = $this->sql_column_add($table, $column_name, $column_data, true);
}
if ($sqlite)
{
if ($column_exists)
{
$sqlite_data[$table]['change_columns'][] = $result;
}
else
{
$sqlite_data[$table]['add_columns'][] = $result;
}
}
else if ($this->return_statements)
{
$statements = array_merge($statements, $result);
}
}
}
}
// Add columns?
if (!empty($schema_changes['add_columns']))
{
foreach ($schema_changes['add_columns'] as $table => $columns)
{
foreach ($columns as $column_name => $column_data)
{
// Only add the column if it does not exist yet
if ($column_exists = $this->sql_column_exists($table, $column_name))
{
continue;
// This is commented out here because it can take tremendous time on updates
// $result = $this->sql_column_change($table, $column_name, $column_data, true);
}
else
{
$result = $this->sql_column_add($table, $column_name, $column_data, true);
}
if ($sqlite)
{
if ($column_exists)
{
continue;
// $sqlite_data[$table]['change_columns'][] = $result;
}
else
{
$sqlite_data[$table]['add_columns'][] = $result;
}
}
else if ($this->return_statements)
{
$statements = array_merge($statements, $result);
}
}
}
}
// Remove keys?
if (!empty($schema_changes['drop_keys']))
{
foreach ($schema_changes['drop_keys'] as $table => $indexes)
{
foreach ($indexes as $index_name)
{
if (!$this->sql_index_exists($table, $index_name) && !$this->sql_unique_index_exists($table, $index_name))
{
continue;
}
$result = $this->sql_index_drop($table, $index_name);
if ($this->return_statements)
{
$statements = array_merge($statements, $result);
}
}
}
}
// Drop columns?
if (!empty($schema_changes['drop_columns']))
{
foreach ($schema_changes['drop_columns'] as $table => $columns)
{
foreach ($columns as $column)
{
// Only remove the column if it exists...
if ($this->sql_column_exists($table, $column))
{
$result = $this->sql_column_remove($table, $column, true);
if ($sqlite)
{
$sqlite_data[$table]['drop_columns'][] = $result;
}
else if ($this->return_statements)
{
$statements = array_merge($statements, $result);
}
}
}
}
}
// Add primary keys?
if (!empty($schema_changes['add_primary_keys']))
{
foreach ($schema_changes['add_primary_keys'] as $table => $columns)
{
$result = $this->sql_create_primary_key($table, $columns, true);
if ($sqlite)
{
$sqlite_data[$table]['primary_key'] = $result;
}
else if ($this->return_statements)
{
$statements = array_merge($statements, $result);
}
}
}
// Add unique indexes?
if (!empty($schema_changes['add_unique_index']))
{
foreach ($schema_changes['add_unique_index'] as $table => $index_array)
{
foreach ($index_array as $index_name => $column)
{
if ($this->sql_unique_index_exists($table, $index_name))
{
continue;
}
$result = $this->sql_create_unique_index($table, $index_name, $column);
if ($this->return_statements)
{
$statements = array_merge($statements, $result);
}
}
}
}
// Add indexes?
if (!empty($schema_changes['add_index']))
{
foreach ($schema_changes['add_index'] as $table => $index_array)
{
foreach ($index_array as $index_name => $column)
{
if ($this->sql_index_exists($table, $index_name))
{
continue;
}
$result = $this->sql_create_index($table, $index_name, $column);
if ($this->return_statements)
{
$statements = array_merge($statements, $result);
}
}
}
}
if ($sqlite)
{
foreach ($sqlite_data as $table_name => $sql_schema_changes)
{
// Create temporary table with original data
$statements[] = 'begin';
$sql = "SELECT sql
FROM sqlite_master
WHERE type = 'table'
AND name = '{$table_name}'
ORDER BY type DESC, name;";
$result = $this->db->sql_query($sql);
if (!$result)
{
continue;
}
$row = $this->db->sql_fetchrow($result);
$this->db->sql_freeresult($result);
// Create a backup table and populate it, destroy the existing one
$statements[] = preg_replace('#CREATE\s+TABLE\s+"?' . $table_name . '"?#i', 'CREATE TEMPORARY TABLE ' . $table_name . '_temp', $row['sql']);
$statements[] = 'INSERT INTO ' . $table_name . '_temp SELECT * FROM ' . $table_name;
$statements[] = 'DROP TABLE ' . $table_name;
// Get the columns...
preg_match('#\((.*)\)#s', $row['sql'], $matches);
$plain_table_cols = trim($matches[1]);
$new_table_cols = preg_split('/,(?![\s\w]+\))/m', $plain_table_cols);
$column_list = array();
foreach ($new_table_cols as $declaration)
{
$entities = preg_split('#\s+#', trim($declaration));
if ($entities[0] == 'PRIMARY')
{
continue;
}
$column_list[] = $entities[0];
}
// note down the primary key notation because sqlite only supports adding it to the end for the new table
$primary_key = false;
$_new_cols = array();
foreach ($new_table_cols as $key => $declaration)
{
$entities = preg_split('#\s+#', trim($declaration));
if ($entities[0] == 'PRIMARY')
{
$primary_key = $declaration;
continue;
}
$_new_cols[] = $declaration;
}
$new_table_cols = $_new_cols;
// First of all... change columns
if (!empty($sql_schema_changes['change_columns']))
{
foreach ($sql_schema_changes['change_columns'] as $column_sql)
{
foreach ($new_table_cols as $key => $declaration)
{
$entities = preg_split('#\s+#', trim($declaration));
if (strpos($column_sql, $entities[0] . ' ') === 0)
{
$new_table_cols[$key] = $column_sql;
}
}
}
}
if (!empty($sql_schema_changes['add_columns']))
{
foreach ($sql_schema_changes['add_columns'] as $column_sql)
{
$new_table_cols[] = $column_sql;
}
}
// Now drop them...
if (!empty($sql_schema_changes['drop_columns']))
{
foreach ($sql_schema_changes['drop_columns'] as $column_name)
{
// Remove from column list...
$new_column_list = array();
foreach ($column_list as $key => $value)
{
if ($value === $column_name)
{
continue;
}
$new_column_list[] = $value;
}
$column_list = $new_column_list;
// Remove from table...
$_new_cols = array();
foreach ($new_table_cols as $key => $declaration)
{
$entities = preg_split('#\s+#', trim($declaration));
if (strpos($column_name . ' ', $entities[0] . ' ') === 0)
{
continue;
}
$_new_cols[] = $declaration;
}
$new_table_cols = $_new_cols;
}
}
// Primary key...
if (!empty($sql_schema_changes['primary_key']))
{
$new_table_cols[] = 'PRIMARY KEY (' . implode(', ', $sql_schema_changes['primary_key']) . ')';
}
// Add a new one or the old primary key
else if ($primary_key !== false)
{
$new_table_cols[] = $primary_key;
}
$columns = implode(',', $column_list);
// create a new table and fill it up. destroy the temp one
$statements[] = 'CREATE TABLE ' . $table_name . ' (' . implode(',', $new_table_cols) . ');';
$statements[] = 'INSERT INTO ' . $table_name . ' (' . $columns . ') SELECT ' . $columns . ' FROM ' . $table_name . '_temp;';
$statements[] = 'DROP TABLE ' . $table_name . '_temp';
$statements[] = 'commit';
}
}
if ($this->return_statements)
{
return $statements;
}
}
/**
* {@inheritDoc}
*/
function sql_list_columns($table_name)
{
$columns = array();
switch ($this->sql_layer)
{
case 'mysql_41':
$sql = "SHOW COLUMNS FROM $table_name";
break;
case 'oracle':
$sql = "SELECT column_name
FROM user_tab_columns
WHERE LOWER(table_name) = '" . strtolower($table_name) . "'";
break;
case 'sqlite3':
$sql = "SELECT sql
FROM sqlite_master
WHERE type = 'table'
AND name = '{$table_name}'";
$result = $this->db->sql_query($sql);
if (!$result)
{
return false;
}
$row = $this->db->sql_fetchrow($result);
$this->db->sql_freeresult($result);
preg_match('#\((.*)\)#s', $row['sql'], $matches);
$cols = trim($matches[1]);
$col_array = preg_split('/,(?![\s\w]+\))/m', $cols);
foreach ($col_array as $declaration)
{
$entities = preg_split('#\s+#', trim($declaration));
if ($entities[0] == 'PRIMARY')
{
continue;
}
$column = strtolower($entities[0]);
$columns[$column] = $column;
}
return $columns;
break;
}
$result = $this->db->sql_query($sql);
while ($row = $this->db->sql_fetchrow($result))
{
$column = strtolower(current($row));
$columns[$column] = $column;
}
$this->db->sql_freeresult($result);
return $columns;
}
/**
* {@inheritDoc}
*/
function sql_column_exists($table_name, $column_name)
{
$columns = $this->sql_list_columns($table_name);
return isset($columns[$column_name]);
}
/**
* {@inheritDoc}
*/
function sql_index_exists($table_name, $index_name)
{
switch ($this->sql_layer)
{
case 'mysql_41':
$sql = 'SHOW KEYS
FROM ' . $table_name;
$col = 'Key_name';
break;
case 'oracle':
$sql = "SELECT index_name
FROM user_indexes
WHERE table_name = '" . strtoupper($table_name) . "'
AND generated = 'N'
AND uniqueness = 'NONUNIQUE'";
$col = 'index_name';
break;
case 'sqlite3':
$sql = "PRAGMA index_list('" . $table_name . "');";
$col = 'name';
break;
}
$result = $this->db->sql_query($sql);
while ($row = $this->db->sql_fetchrow($result))
{
if ($this->sql_layer == 'mysql_41' && !$row['Non_unique'])
{
continue;
}
switch ($this->sql_layer)
{
// These DBMS prefix index name with the table name
case 'oracle':
case 'sqlite3':
$new_index_name = $this->check_index_name_length($table_name, $table_name . '_' . $index_name, false);
break;
default:
$new_index_name = $this->check_index_name_length($table_name, $index_name, false);
break;
}
if (strtolower($row[$col]) == strtolower($new_index_name))
{
$this->db->sql_freeresult($result);
return true;
}
}
$this->db->sql_freeresult($result);
return false;
}
/**
* {@inheritDoc}
*/
function sql_unique_index_exists($table_name, $index_name)
{
switch ($this->sql_layer)
{
case 'mysql_41':
$sql = 'SHOW KEYS
FROM ' . $table_name;
$col = 'Key_name';
break;
case 'oracle':
$sql = "SELECT index_name, table_owner
FROM user_indexes
WHERE table_name = '" . strtoupper($table_name) . "'
AND generated = 'N'
AND uniqueness = 'UNIQUE'";
$col = 'index_name';
break;
case 'sqlite3':
$sql = "PRAGMA index_list('" . $table_name . "');";
$col = 'name';
break;
}
$result = $this->db->sql_query($sql);
while ($row = $this->db->sql_fetchrow($result))
{
if ($this->sql_layer == 'mysql_41' && ($row['Non_unique'] || $row[$col] == 'PRIMARY'))
{
continue;
}
if ($this->sql_layer == 'sqlite3' && !$row['unique'])
{
continue;
}
// These DBMS prefix index name with the table name
switch ($this->sql_layer)
{
case 'oracle':
// Two cases here... prefixed with U_[table_owner] and not prefixed with table_name
if (strpos($row[$col], 'U_') === 0)
{
$row[$col] = substr($row[$col], strlen('U_' . $row['table_owner']) + 1);
}
else if (strpos($row[$col], strtoupper($table_name)) === 0)
{
$row[$col] = substr($row[$col], strlen($table_name) + 1);
}
break;
case 'sqlite3':
$row[$col] = substr($row[$col], strlen($table_name) + 1);
break;
}
if (strtolower($row[$col]) == strtolower($index_name))
{
$this->db->sql_freeresult($result);
return true;
}
}
$this->db->sql_freeresult($result);
return false;
}
/**
* Private method for performing sql statements (either execute them or return them)
* @access private
*/
function _sql_run_sql($statements)
{
if ($this->return_statements)
{
return $statements;
}
// We could add error handling here...
foreach ($statements as $sql)
{
if ($sql === 'begin')
{
$this->db->sql_transaction('begin');
}
else if ($sql === 'commit')
{
$this->db->sql_transaction('commit');
}
else
{
$this->db->sql_query($sql);
}
}
return true;
}
/**
* Function to prepare some column information for better usage
* @access private
*/
function sql_prepare_column_data($table_name, $column_name, $column_data)
{
if (strlen($column_name) > 30)
{
trigger_error("Column name '$column_name' on table '$table_name' is too long. The maximum is 30 characters.", E_USER_ERROR);
}
// Get type
list($column_type) = $this->get_column_type($column_data[0]);
// Adjust default value if db-dependent specified
if (is_array($column_data[1]))
{
$column_data[1] = (isset($column_data[1][$this->sql_layer])) ? $column_data[1][$this->sql_layer] : $column_data[1]['default'];
}
$sql = '';
$return_array = array();
switch ($this->sql_layer)
{
case 'mysql_41':
$sql .= " {$column_type} ";
// For hexadecimal values do not use single quotes
if (!is_null($column_data[1]) && substr($column_type, -4) !== 'text' && substr($column_type, -4) !== 'blob')
{
$sql .= (strpos($column_data[1], '0x') === 0) ? "DEFAULT {$column_data[1]} " : "DEFAULT '{$column_data[1]}' ";
}
if (!is_null($column_data[1]) || (isset($column_data[2]) && $column_data[2] == 'auto_increment'))
{
$sql .= 'NOT NULL';
}
else
{
$sql .= 'NULL';
}
if (isset($column_data[2]))
{
if ($column_data[2] == 'auto_increment')
{
$sql .= ' auto_increment';
}
else if ($this->sql_layer === 'mysql_41' && $column_data[2] == 'true_sort')
{
$sql .= ' COLLATE utf8_unicode_ci';
}
}
if (isset($column_data['after']))
{
$return_array['after'] = $column_data['after'];
}
break;
case 'oracle':
$sql .= " {$column_type} ";
$sql .= (!is_null($column_data[1])) ? "DEFAULT '{$column_data[1]}' " : '';
// In Oracle empty strings ('') are treated as NULL.
// Therefore in oracle we allow NULL's for all DEFAULT '' entries
// Oracle does not like setting NOT NULL on a column that is already NOT NULL (this happens only on number fields)
if (!preg_match('/number/i', $column_type))
{
$sql .= ($column_data[1] === '' || $column_data[1] === null) ? '' : 'NOT NULL';
}
$return_array['auto_increment'] = false;
if (isset($column_data[2]) && $column_data[2] == 'auto_increment')
{
$return_array['auto_increment'] = true;
}
break;
case 'sqlite3':
$return_array['primary_key_set'] = false;
if (isset($column_data[2]) && $column_data[2] == 'auto_increment')
{
$sql .= ' INTEGER PRIMARY KEY AUTOINCREMENT';
$return_array['primary_key_set'] = true;
}
else
{
$sql .= ' ' . $column_type;
}
if (!is_null($column_data[1]))
{
$sql .= ' NOT NULL ';
$sql .= "DEFAULT '{$column_data[1]}'";
}
break;
}
$return_array['column_type_sql'] = $sql;
return $return_array;
}
/**
* Get the column's database type from the type map
*
* @param string $column_map_type
* @return array column type for this database
* and map type without length
*/
function get_column_type($column_map_type)
{
$column_type = '';
if (strpos($column_map_type, ':') !== false)
{
list($orig_column_type, $column_length) = explode(':', $column_map_type);
if (!is_array($this->dbms_type_map[$this->sql_layer][$orig_column_type . ':']))
{
$column_type = sprintf($this->dbms_type_map[$this->sql_layer][$orig_column_type . ':'], $column_length);
}
else
{
if (isset($this->dbms_type_map[$this->sql_layer][$orig_column_type . ':']['rule']))
{
switch ($this->dbms_type_map[$this->sql_layer][$orig_column_type . ':']['rule'][0])
{
case 'div':
$column_length /= $this->dbms_type_map[$this->sql_layer][$orig_column_type . ':']['rule'][1];
$column_length = ceil($column_length);
$column_type = sprintf($this->dbms_type_map[$this->sql_layer][$orig_column_type . ':'][0], $column_length);
break;
}
}
if (isset($this->dbms_type_map[$this->sql_layer][$orig_column_type . ':']['limit']))
{
switch ($this->dbms_type_map[$this->sql_layer][$orig_column_type . ':']['limit'][0])
{
case 'mult':
$column_length *= $this->dbms_type_map[$this->sql_layer][$orig_column_type . ':']['limit'][1];
if ($column_length > $this->dbms_type_map[$this->sql_layer][$orig_column_type . ':']['limit'][2])
{
$column_type = $this->dbms_type_map[$this->sql_layer][$orig_column_type . ':']['limit'][3];
}
else
{
$column_type = sprintf($this->dbms_type_map[$this->sql_layer][$orig_column_type . ':'][0], $column_length);
}
break;
}
}
}
$orig_column_type .= ':';
}
else
{
$orig_column_type = $column_map_type;
$column_type = $this->dbms_type_map[$this->sql_layer][$column_map_type];
}
return array($column_type, $orig_column_type);
}
/**
* {@inheritDoc}
*/
function sql_column_add($table_name, $column_name, $column_data, $inline = false)
{
$column_data = $this->sql_prepare_column_data($table_name, $column_name, $column_data);
$statements = array();
switch ($this->sql_layer)
{
case 'mysql_41':
$after = (!empty($column_data['after'])) ? ' AFTER ' . $column_data['after'] : '';
$statements[] = 'ALTER TABLE `' . $table_name . '` ADD COLUMN `' . $column_name . '` ' . $column_data['column_type_sql'] . $after;
break;
case 'oracle':
// Does not support AFTER, only through temporary table
$statements[] = 'ALTER TABLE ' . $table_name . ' ADD ' . $column_name . ' ' . $column_data['column_type_sql'];
break;
case 'sqlite3':
if ($inline && $this->return_statements)
{
return $column_name . ' ' . $column_data['column_type_sql'];
}
$statements[] = 'ALTER TABLE ' . $table_name . ' ADD ' . $column_name . ' ' . $column_data['column_type_sql'];
break;
}
return $this->_sql_run_sql($statements);
}
/**
* {@inheritDoc}
*/
function sql_column_remove($table_name, $column_name, $inline = false)
{
$statements = array();
switch ($this->sql_layer)
{
case 'mysql_41':
$statements[] = 'ALTER TABLE `' . $table_name . '` DROP COLUMN `' . $column_name . '`';
break;
case 'oracle':
$statements[] = 'ALTER TABLE ' . $table_name . ' DROP COLUMN ' . $column_name;
break;
case 'sqlite3':
if ($inline && $this->return_statements)
{
return $column_name;
}
$recreate_queries = $this->sqlite_get_recreate_table_queries($table_name, $column_name);
if (empty($recreate_queries))
{
break;
}
$statements[] = 'begin';
$sql_create_table = array_shift($recreate_queries);
// Create a backup table and populate it, destroy the existing one
$statements[] = preg_replace('#CREATE\s+TABLE\s+"?' . $table_name . '"?#i', 'CREATE TEMPORARY TABLE ' . $table_name . '_temp', $sql_create_table);
$statements[] = 'INSERT INTO ' . $table_name . '_temp SELECT * FROM ' . $table_name;
$statements[] = 'DROP TABLE ' . $table_name;
preg_match('#\((.*)\)#s', $sql_create_table, $matches);
$new_table_cols = trim($matches[1]);
$old_table_cols = preg_split('/,(?![\s\w]+\))/m', $new_table_cols);
$column_list = array();
foreach ($old_table_cols as $declaration)
{
$entities = preg_split('#\s+#', trim($declaration));
if ($entities[0] == 'PRIMARY' || $entities[0] === $column_name)
{
continue;
}
$column_list[] = $entities[0];
}
$columns = implode(',', $column_list);
$new_table_cols = trim(preg_replace('/' . $column_name . '\b[^,]+(?:,|$)/m', '', $new_table_cols));
if (substr($new_table_cols, -1) === ',')
{
// Remove the comma from the last entry again
$new_table_cols = substr($new_table_cols, 0, -1);
}
// create a new table and fill it up. destroy the temp one
$statements[] = 'CREATE TABLE ' . $table_name . ' (' . $new_table_cols . ');';
$statements = array_merge($statements, $recreate_queries);
$statements[] = 'INSERT INTO ' . $table_name . ' (' . $columns . ') SELECT ' . $columns . ' FROM ' . $table_name . '_temp;';
$statements[] = 'DROP TABLE ' . $table_name . '_temp';
$statements[] = 'commit';
break;
}
return $this->_sql_run_sql($statements);
}
/**
* {@inheritDoc}
*/
function sql_index_drop($table_name, $index_name)
{
$statements = array();
switch ($this->sql_layer)
{
case 'mysql_41':
$index_name = $this->check_index_name_length($table_name, $index_name, false);
$statements[] = 'DROP INDEX ' . $index_name . ' ON ' . $table_name;
break;
case 'oracle':
case 'sqlite3':
$index_name = $this->check_index_name_length($table_name, $table_name . '_' . $index_name, false);
$statements[] = 'DROP INDEX ' . $index_name;
break;
}
return $this->_sql_run_sql($statements);
}
/**
* {@inheritDoc}
*/
function sql_table_drop($table_name)
{
$statements = array();
if (!$this->sql_table_exists($table_name))
{
return $this->_sql_run_sql($statements);
}
// the most basic operation, get rid of the table
$statements[] = 'DROP TABLE ' . $table_name;
switch ($this->sql_layer)
{
case 'oracle':
$sql = 'SELECT A.REFERENCED_NAME
FROM USER_DEPENDENCIES A, USER_TRIGGERS B
WHERE A.REFERENCED_TYPE = \'SEQUENCE\'
AND A.NAME = B.TRIGGER_NAME
AND B.TABLE_NAME = \'' . strtoupper($table_name) . "'";
$result = $this->db->sql_query($sql);
// any sequences ref'd to this table's triggers?
while ($row = $this->db->sql_fetchrow($result))
{
$statements[] = "DROP SEQUENCE {$row['referenced_name']}";
}
$this->db->sql_freeresult($result);
break;
}
return $this->_sql_run_sql($statements);
}
/**
* {@inheritDoc}
*/
function sql_create_primary_key($table_name, $column, $inline = false)
{
$statements = array();
switch ($this->sql_layer)
{
case 'mysql_41':
$statements[] = 'ALTER TABLE ' . $table_name . ' ADD PRIMARY KEY (' . implode(', ', $column) . ')';
break;
case 'oracle':
$statements[] = 'ALTER TABLE ' . $table_name . ' add CONSTRAINT pk_' . $table_name . ' PRIMARY KEY (' . implode(', ', $column) . ')';
break;
case 'sqlite3':
if ($inline && $this->return_statements)
{
return $column;
}
$recreate_queries = $this->sqlite_get_recreate_table_queries($table_name);
if (empty($recreate_queries))
{
break;
}
$statements[] = 'begin';
$sql_create_table = array_shift($recreate_queries);
// Create a backup table and populate it, destroy the existing one
$statements[] = preg_replace('#CREATE\s+TABLE\s+"?' . $table_name . '"?#i', 'CREATE TEMPORARY TABLE ' . $table_name . '_temp', $sql_create_table);
$statements[] = 'INSERT INTO ' . $table_name . '_temp SELECT * FROM ' . $table_name;
$statements[] = 'DROP TABLE ' . $table_name;
preg_match('#\((.*)\)#s', $sql_create_table, $matches);
$new_table_cols = trim($matches[1]);
$old_table_cols = preg_split('/,(?![\s\w]+\))/m', $new_table_cols);
$column_list = array();
foreach ($old_table_cols as $declaration)
{
$entities = preg_split('#\s+#', trim($declaration));
if ($entities[0] == 'PRIMARY')
{
continue;
}
$column_list[] = $entities[0];
}
$columns = implode(',', $column_list);
// create a new table and fill it up. destroy the temp one
$statements[] = 'CREATE TABLE ' . $table_name . ' (' . $new_table_cols . ', PRIMARY KEY (' . implode(', ', $column) . '));';
$statements = array_merge($statements, $recreate_queries);
$statements[] = 'INSERT INTO ' . $table_name . ' (' . $columns . ') SELECT ' . $columns . ' FROM ' . $table_name . '_temp;';
$statements[] = 'DROP TABLE ' . $table_name . '_temp';
$statements[] = 'commit';
break;
}
return $this->_sql_run_sql($statements);
}
/**
* {@inheritDoc}
*/
function sql_create_unique_index($table_name, $index_name, $column)
{
$statements = array();
switch ($this->sql_layer)
{
case 'oracle':
case 'sqlite3':
$index_name = $this->check_index_name_length($table_name, $table_name . '_' . $index_name);
$statements[] = 'CREATE UNIQUE INDEX ' . $index_name . ' ON ' . $table_name . '(' . implode(', ', $column) . ')';
break;
case 'mysql_41':
$index_name = $this->check_index_name_length($table_name, $index_name);
$statements[] = 'ALTER TABLE ' . $table_name . ' ADD UNIQUE INDEX ' . $index_name . '(' . implode(', ', $column) . ')';
break;
}
return $this->_sql_run_sql($statements);
}
/**
* {@inheritDoc}
*/
function sql_create_index($table_name, $index_name, $column)
{
$statements = array();
$column = preg_replace('#:.*$#', '', $column);
switch ($this->sql_layer)
{
case 'oracle':
case 'sqlite3':
$index_name = $this->check_index_name_length($table_name, $table_name . '_' . $index_name);
$statements[] = 'CREATE INDEX ' . $index_name . ' ON ' . $table_name . '(' . implode(', ', $column) . ')';
break;
case 'mysql_41':
$index_name = $this->check_index_name_length($table_name, $index_name);
$statements[] = 'ALTER TABLE ' . $table_name . ' ADD INDEX ' . $index_name . ' (' . implode(', ', $column) . ')';
break;
}
return $this->_sql_run_sql($statements);
}
/**
* Check whether the index name is too long
*
* @param string $table_name
* @param string $index_name
* @param bool $throw_error
* @return string The index name, shortened if too long
*/
protected function check_index_name_length($table_name, $index_name, $throw_error = true)
{
$max_index_name_length = $this->get_max_index_name_length();
if (strlen($index_name) > $max_index_name_length)
{
// Try removing the table prefix if it's at the beginning
$table_prefix = substr(CONFIG_TABLE, 0, -6); // strlen(config)
if (strpos($index_name, $table_prefix) === 0)
{
$index_name = substr($index_name, strlen($table_prefix));
return $this->check_index_name_length($table_name, $index_name, $throw_error);
}
// Try removing the remaining suffix part of table name then
$table_suffix = substr($table_name, strlen($table_prefix));
if (strpos($index_name, $table_suffix) === 0)
{
// Remove the suffix and underscore separator between table_name and index_name
$index_name = substr($index_name, strlen($table_suffix) + 1);
return $this->check_index_name_length($table_name, $index_name, $throw_error);
}
if ($throw_error)
{
trigger_error("Index name '$index_name' on table '$table_name' is too long. The maximum is $max_index_name_length characters.", E_USER_ERROR);
}
}
return $index_name;
}
/**
* Get maximum index name length. Might vary depending on db type
*
* @return int Maximum index name length
*/
protected function get_max_index_name_length()
{
return 30;
}
/**
* {@inheritDoc}
*/
function sql_list_index($table_name)
{
$index_array = array();
switch ($this->sql_layer)
{
case 'mysql_41':
$sql = 'SHOW KEYS
FROM ' . $table_name;
$col = 'Key_name';
break;
case 'oracle':
$sql = "SELECT index_name
FROM user_indexes
WHERE table_name = '" . strtoupper($table_name) . "'
AND generated = 'N'
AND uniqueness = 'NONUNIQUE'";
$col = 'index_name';
break;
case 'sqlite3':
$sql = "PRAGMA index_info('" . $table_name . "');";
$col = 'name';
break;
}
$result = $this->db->sql_query($sql);
while ($row = $this->db->sql_fetchrow($result))
{
if ($this->sql_layer == 'mysql_41' && !$row['Non_unique'])
{
continue;
}
switch ($this->sql_layer)
{
case 'oracle':
case 'sqlite3':
$row[$col] = substr($row[$col], strlen($table_name) + 1);
break;
}
$index_array[] = $row[$col];
}
$this->db->sql_freeresult($result);
return array_map('strtolower', $index_array);
}
/**
* Removes table_name from the index_name if it is at the beginning
*
* @param $table_name
* @param $index_name
* @return string
*/
protected function strip_table_name_from_index_name($table_name, $index_name)
{
return (strpos(strtoupper($index_name), strtoupper($table_name)) === 0) ? substr($index_name, strlen($table_name) + 1) : $index_name;
}
/**
* {@inheritDoc}
*/
function sql_column_change($table_name, $column_name, $column_data, $inline = false)
{
$original_column_data = $column_data;
$column_data = $this->sql_prepare_column_data($table_name, $column_name, $column_data);
$statements = array();
switch ($this->sql_layer)
{
case 'mysql_41':
$statements[] = 'ALTER TABLE `' . $table_name . '` CHANGE `' . $column_name . '` `' . $column_name . '` ' . $column_data['column_type_sql'];
break;
case 'oracle':
// We need the data here
$old_return_statements = $this->return_statements;
$this->return_statements = true;
// Get list of existing indexes
$indexes = $this->get_existing_indexes($table_name, $column_name);
$unique_indexes = $this->get_existing_indexes($table_name, $column_name, true);
// Drop any indexes
if (!empty($indexes) || !empty($unique_indexes))
{
$drop_indexes = array_merge(array_keys($indexes), array_keys($unique_indexes));
foreach ($drop_indexes as $index_name)
{
$result = $this->sql_index_drop($table_name, $this->strip_table_name_from_index_name($table_name, $index_name));
$statements = array_merge($statements, $result);
}
}
$temp_column_name = 'temp_' . substr(md5($column_name), 0, 25);
// Add a temporary table with the new type
$result = $this->sql_column_add($table_name, $temp_column_name, $original_column_data);
$statements = array_merge($statements, $result);
// Copy the data to the new column
$statements[] = 'UPDATE ' . $table_name . ' SET ' . $temp_column_name . ' = ' . $column_name;
// Drop the original column
$result = $this->sql_column_remove($table_name, $column_name);
$statements = array_merge($statements, $result);
// Recreate the original column with the new type
$result = $this->sql_column_add($table_name, $column_name, $original_column_data);
$statements = array_merge($statements, $result);
if (!empty($indexes))
{
// Recreate indexes after we changed the column
foreach ($indexes as $index_name => $index_data)
{
$result = $this->sql_create_index($table_name, $this->strip_table_name_from_index_name($table_name, $index_name), $index_data);
$statements = array_merge($statements, $result);
}
}
if (!empty($unique_indexes))
{
// Recreate unique indexes after we changed the column
foreach ($unique_indexes as $index_name => $index_data)
{
$result = $this->sql_create_unique_index($table_name, $this->strip_table_name_from_index_name($table_name, $index_name), $index_data);
$statements = array_merge($statements, $result);
}
}
// Copy the data to the original column
$statements[] = 'UPDATE ' . $table_name . ' SET ' . $column_name . ' = ' . $temp_column_name;
// Drop the temporary column again
$result = $this->sql_column_remove($table_name, $temp_column_name);
$statements = array_merge($statements, $result);
$this->return_statements = $old_return_statements;
break;
case 'sqlite3':
if ($inline && $this->return_statements)
{
return $column_name . ' ' . $column_data['column_type_sql'];
}
$recreate_queries = $this->sqlite_get_recreate_table_queries($table_name);
if (empty($recreate_queries))
{
break;
}
$statements[] = 'begin';
$sql_create_table = array_shift($recreate_queries);
// Create a temp table and populate it, destroy the existing one
$statements[] = preg_replace('#CREATE\s+TABLE\s+"?' . $table_name . '"?#i', 'CREATE TEMPORARY TABLE ' . $table_name . '_temp', $sql_create_table);
$statements[] = 'INSERT INTO ' . $table_name . '_temp SELECT * FROM ' . $table_name;
$statements[] = 'DROP TABLE ' . $table_name;
preg_match('#\((.*)\)#s', $sql_create_table, $matches);
$new_table_cols = trim($matches[1]);
$old_table_cols = preg_split('/,(?![\s\w]+\))/m', $new_table_cols);
$column_list = array();
foreach ($old_table_cols as $key => $declaration)
{
$declaration = trim($declaration);
// Check for the beginning of the constraint section and stop
if (preg_match('/[^\(]*\s*PRIMARY KEY\s+\(/', $declaration) ||
preg_match('/[^\(]*\s*UNIQUE\s+\(/', $declaration) ||
preg_match('/[^\(]*\s*FOREIGN KEY\s+\(/', $declaration) ||
preg_match('/[^\(]*\s*CHECK\s+\(/', $declaration))
{
break;
}
$entities = preg_split('#\s+#', $declaration);
$column_list[] = $entities[0];
if ($entities[0] == $column_name)
{
$old_table_cols[$key] = $column_name . ' ' . $column_data['column_type_sql'];
}
}
$columns = implode(',', $column_list);
// Create a new table and fill it up. destroy the temp one
$statements[] = 'CREATE TABLE ' . $table_name . ' (' . implode(',', $old_table_cols) . ');';
$statements = array_merge($statements, $recreate_queries);
$statements[] = 'INSERT INTO ' . $table_name . ' (' . $columns . ') SELECT ' . $columns . ' FROM ' . $table_name . '_temp;';
$statements[] = 'DROP TABLE ' . $table_name . '_temp';
$statements[] = 'commit';
break;
}
return $this->_sql_run_sql($statements);
}
/**
* Get a list with existing indexes for the column
*
* @param string $table_name
* @param string $column_name
* @param bool $unique Should we get unique indexes or normal ones
* @return array Array with Index name => columns
*/
public function get_existing_indexes($table_name, $column_name, $unique = false)
{
switch ($this->sql_layer)
{
case 'mysql_41':
case 'sqlite3':
// Not supported
throw new \Exception('DBMS is not supported');
break;
}
$sql = '';
$existing_indexes = array();
switch ($this->sql_layer)
{
case 'oracle':
$sql = "SELECT ix.index_name AS phpbb_index_name, ix.uniqueness AS is_unique
FROM all_ind_columns ixc, all_indexes ix
WHERE ix.index_name = ixc.index_name
AND ixc.table_name = '" . strtoupper($table_name) . "'
AND ixc.column_name = '" . strtoupper($column_name) . "'";
break;
}
$result = $this->db->sql_query($sql);
while ($row = $this->db->sql_fetchrow($result))
{
if (!isset($row['is_unique']) || ($unique && $row['is_unique'] == 'UNIQUE') || (!$unique && $row['is_unique'] == 'NONUNIQUE'))
{
$existing_indexes[$row['phpbb_index_name']] = array();
}
}
$this->db->sql_freeresult($result);
if (empty($existing_indexes))
{
return array();
}
switch ($this->sql_layer)
{
case 'oracle':
$sql = "SELECT index_name AS phpbb_index_name, column_name AS phpbb_column_name
FROM all_ind_columns
WHERE table_name = '" . strtoupper($table_name) . "'
AND " . $this->db->sql_in_set('index_name', array_keys($existing_indexes));
break;
}
$result = $this->db->sql_query($sql);
while ($row = $this->db->sql_fetchrow($result))
{
$existing_indexes[$row['phpbb_index_name']][] = $row['phpbb_column_name'];
}
$this->db->sql_freeresult($result);
return $existing_indexes;
}
/**
* Returns the Queries which are required to recreate a table including indexes
*
* @param string $table_name
* @param string $remove_column When we drop a column, we remove the column
* from all indexes. If the index has no other
* column, we drop it completly.
* @return array
*/
protected function sqlite_get_recreate_table_queries($table_name, $remove_column = '')
{
$queries = array();
$sql = "SELECT sql
FROM sqlite_master
WHERE type = 'table'
AND name = '{$table_name}'";
$result = $this->db->sql_query($sql);
$sql_create_table = $this->db->sql_fetchfield('sql');
$this->db->sql_freeresult($result);
if (!$sql_create_table)
{
return array();
}
$queries[] = $sql_create_table;
$sql = "SELECT sql
FROM sqlite_master
WHERE type = 'index'
AND tbl_name = '{$table_name}'";
$result = $this->db->sql_query($sql);
while ($sql_create_index = $this->db->sql_fetchfield('sql'))
{
if ($remove_column)
{
$match = array();
preg_match('#(?:[\w ]+)\((.*)\)#', $sql_create_index, $match);
if (!isset($match[1]))
{
continue;
}
// Find and remove $remove_column from the index
$columns = explode(', ', $match[1]);
$found_column = array_search($remove_column, $columns);
if ($found_column !== false)
{
unset($columns[$found_column]);
// If the column list is not empty add the index to the list
if (!empty($columns))
{
$queries[] = str_replace($match[1], implode(', ', $columns), $sql_create_index);
}
}
else
{
$queries[] = $sql_create_index;
}
}
else
{
$queries[] = $sql_create_index;
}
}
$this->db->sql_freeresult($result);
return $queries;
}
}